bash: listen on tcp port

[Chuck]

Is there a way to get a bash script to listen for connections on a tcp
port? I've tried "< /dev/tcp/localhost/1521" but that just throws a
"connection refused" error. Thanks

[Dave B]

Chuck wrote:

That tries to connect to port 1521 on localhost. If there's no program
listening there, you get "connection refused".
I don't think what you want to do can be achieved with bash alone (if that's
not correct, hopefully more knowledgeable users will correct me). I think
that doing what you want requires some external utility, like eg netcat.

--
echo 0|sed 's909=oO#3u)o19;s0#0ooo)].O0;s()(0bu}=(;s#}#.1m"?0^2{#;
s)")9v2@3%"9$);so%op]t(p$e#!o;sz(z^+.z;su+ur!z"au;sxzxd?_{h)cx;:b;
s/\(\(.\).\)\(\(..\)*\)\(\(.\).\)\(\(..\)*#.*\6.*\2.*\)/\5\3\1\7/;
tb'|awk '{while((i+=2)<=length($1)-18)a=a substr($1,i,1);print a}'

[Maxwell Lol]

Chuck <chuckh19...@gmail.com> writes:

You can use the netcat program.

nc -l -p portnumber | script

[Dan Stromberg]

inetd or xinetd are relatively easy ways of getting a bash script
listening on a port. With them, you can make your bash script run once
for each connection - and you don't need to deal with any socket API's -
just the usual stdin/stdout work fine.

Or another way, which is similar to netcat but written in a scripting
language itself, is my pnetcat program:

http://stromberg.dnsalias.org/~strombrg/pnetcat.html

ISTR pnetcat being faster than netcat on gigabit networks at one time
(perhaps it's still true, dunno), because although pnetcat is in a VHLL,
it allows you to specify block sizes and TCP window sizes. In fact, I
wrote it when I was doing some (optically switched) gigE performance
testing - it was able to get over of 900 Megabits/second on a CPU that
wasn't that blazing with modest tuning.

[Burkhard Ott]

vi /etc/inetd.conf

12345 stream tcp nowait root /usr/sbin/tcpd /bin/bash -i

restart inetd

But that might be dangerous because ther is an interactive root shell
listen on purt 12345.

cheers

[mop2]

Not bash alone.
Possibly helpful:
http://groups.google.com/group/comp.unix.shell/browse_thread/thread/92797eb340fe40dd

[Chuck]

I don't think that's available on Solaris 10. Sorry for not including
the platform on my OP.

Also I do not have access to inetd.conf as I am not the administrator on
the box in question.

[Kenny McCormack]

In article <amsdk.1190$Ae3.188@trnddc05>,

Chuck <chuckh19...@gmail.com> wrote:
>Maxwell Lol wrote:
>> Chuck <chuckh19...@gmail.com> writes:
>>
>>> Is there a way to get a bash script to listen for connections on a tcp
>>> port? I've tried "< /dev/tcp/localhost/1521" but that just throws a
>>> "connection refused" error. Thanks
>>
>> You can use the netcat program.
>>
>> nc -l -p portnumber | script
>>
>
>I don't think that's available on Solaris 10. Sorry for not including
>the platform on my OP.

Does the box have an internet connection?

[Maxwell Lol]

Chuck <chuckh19...@gmail.com> writes:

> Maxwell Lol wrote:
>> Chuck <chuckh19...@gmail.com> writes:
>>
>>> Is there a way to get a bash script to listen for connections on a tcp
>>> port? I've tried "< /dev/tcp/localhost/1521" but that just throws a
>>> "connection refused" error. Thanks
>>
>> You can use the netcat program.
>>
>> nc -l -p portnumber | script
>>
>
> I don't think that's available on Solaris 10. Sorry for not including
> the platform on my OP.

Why is that a problem?

It's open source and should compile on Solaris.
Downlaod from
http://osdn.dl.sourceforge.net/sourceforge/netcat/netcat-0.7.1.tar.gz

AFAIK You don't need special priviledges to run it as long as it's not using
a reserved port.

Download it, unzip it. Type

./configure CC=/usr/local/bin/gcc (or whatever)
make (or gmake)

and you are set. Unless you don't have any compilers on your machine....

[Maxwell Lol]

gaz...@xmission.xmission.com (Kenny McCormack) writes:

>>> You can use the netcat program.
>>>
>>> nc -l -p portnumber | script
>>>
>>
>>I don't think that's available on Solaris 10. Sorry for not including
>>the platform on my OP.
>
> Does the box have an internet connection?

Or a USB drive, CDROM, .....

[Chuck]

No but I can pull stuff down to my workstation and upload it with scp.

[Chuck]

Maxwell Lol wrote:

>
> Download it, unzip it. Type
>
> ./configure CC=/usr/local/bin/gcc (or whatever)
> make (or gmake)
>
> and you are set. Unless you don't have any compilers on your machine....
>

I believe so. It's an Oracle DB server and IIRC the Oracle installer
requires cc and make to link it's binaries with only the options you select.

[Kenny McCormack]

In article <d4Ndk.17$jS4.14@trnddc07>,

Does that work with the dixie-cups-and-strings method of communication?

Or does it use the internet like most versions of scp do?

[Chuck]

Any network program - scp or otherwise - can only use the internet if
the host is connected to it.

I think you are confusing tcp/ip with the internet. TCP/IP is a suite of
protocols that can be used on any network. The internet is a network.

[mik3...@gmail.com]

On Jul 11, 2:16 am, Chuck <chuckh1958_nos...@gmail.com> wrote:
> Maxwell Lol wrote:

Solaris has Perl, how about doing some socket programming :
http://www.tutorialspoint.com/perl/perl_socket.htm

[franzi]

Solaris got dtrace and with bash you can useit very well

[Chuck]

franzi wrote:

> Solaris got dtrace and with bash you can useit very well

How would I use it to set up a listener on a port that just does
something trivial like pass back "hello" if someone tries to connect to it?